[Image above] Credit: Mike; Flickr CC BY 2.0

Know what goes great with that burger? Science! Because perfect grill marks aren’t just the measure of a true grill master—there’s chemistry involved.

If you want a crash course in all-things meat chemistry, the latest video from American Chemical Society’s Reaction series has you covered.

Take a look at your uncooked steak or burger. What makes the meat red? ACS explains that beef, for example, is made up of slow twitch muscles—muscles that are used for long periods of time and require a lot of energy. To compensate for that expended energy, a protein called myoglobin helps store oxygen inside the muscle’s cells to provide a consistent energy supply. The more myoglobin present, the deeper the red pigment.


Model of helical domains in myoglobin. Credit: AzaToth [Public domain], via Wikimedia Commons

What about the juiciness factor? Meat is composed of protein and fat, and the lean protein part is about 60% water. When you grind meat, the pulverization of the lean, water-rich muscle fibers releases that trapped moisture you want to keep locked in for a juicier cooked burger. One trick used by grill masters is to actually add water back into ground meat—just add a couple tablespoons of ice-cold water to the mixture before forming patties. 

When you toss meat on the grill, myoglobin starts to transform. As ACS illustrates in the video, once temps exceed 60 °C (140 °F), myoglobin can’t hold on to the oxygen anymore, which causes the steak or burger to turn a tan color.

And now the table is set for one of the most important flavor-producing reactions in the culinary sphere: the Maillard reaction, named after Louis-Camille Maillard, the French chemist who first described the process in 1912 during an attempt to reproduce biological protein synthesis. 

Although it’s sometimes called the “browning reaction,” there’s more to it than that. It’s a specific type of chemical reaction between amino acids and reducing sugars that creates brown pigments in cooked meat and gives browned food that rich, complex flavor. (Think seared steaks, pan-fried dumplings, grilled breads, fried onions, and roasted coffee. Hungry yet?) 

ACS also settles the gas versus charcoal debate. Sure, gas is a cleaner, quicker option. But did you know grilling with charcoal and/or wood chips produces unique aromatic compounds that permeate your food to enhance the flavor? Gas can’t hold a flame to that.

One word of caution: take it easy on the char. If you overcook your food, it not only detracts from the flavor and texture, but also produces carcinogenic compounds that could be avoided with a little low-and-slow grill technique. An effective approach is to set up hot and cool zones on the grill, so your meat can catch a break from the intense heat while it reaches safe internal temperature.

And, for the perfect cookout, resist the temptation to press your spatula into the meat. I know, the sizzle it makes as the juices hit the coals is totally satisfying—but squeezing out those juices equates to squeezing out flavor. And nobody’s going to set off any celebratory fireworks for a dry, insipid burger. 

Check out the video below and let that grill chemistry knowledge marinate before your July 4th cookout!

Credit: American Chemical Society; YouTube